The process of manufacturing semiconductor devices can require many sequential steps accounting for hundreds or even thousands of process variables. Further, tools used carry out the process steps have various specifications, limitations, and requirements that add further variables to the manufacturing process. Thus, process engineers produce semiconductor process recipes (“recipes”) that dictate the process steps and how such steps are to be performed for each tool used in the process.
An incorrect recipe can result in poor results and possibly even damage to the semiconductor wafers being processed. The allowable operating window for a given tool may be well-defined, but also quite complex. Due to such complexity, process engineers can mistakenly create a recipe that is incorrect in some way or otherwise falls outside of the defined operating window for the tool. Thus, recipes must be validated before they are used during manufacturing.
Typically, recipes are validating manually, whereby the process engineer cross-references the recipe with documents detailing the specifications and operating window of a particular tool. Manually validating a recipe is labor-intensive and error-prone. Attempts to automate the recipe validation process have typically centered on using a spreadsheet to verify that recipe parameters fall within allowed limits. While this provides some degree of validation, such a process can be inadequate if there are complex conditions involving combinations of several parameters. Even more difficult is validating that the order and types of steps in a recipe meet the operating window requirements of a given tool.
Accordingly, the inventors have provided an improved method and apparatus for automated validation of semiconductor process steps.